Syringe filter, needle sample filter, small filter head, etc., are a kind of filter connected to the front of the syringe. In HPLC analysis, the particle size of the chromatographic column packing is small, and it is easy to be blocked by impurity particles.
Therefore, the sample and solvent need to be pre-filtered to remove particulate contaminants and protect the instrument. Ion chromatography, which is commonly used in environmental analysis, also requires that no inorganic contaminants can be introduced into the sample preparation. The syringe filter can be used in HPLC analysis and IC analysis. Filtering the sample solution is an important step in the sample preparation process. The filter adopts today's advanced detection methods and production technology to produce a syringe filter with high quality, and the product quality far exceeds that of other domestic counterparts.
Syringe filter is widely used in the laboratory, no need to change the membrane and clean the filter, saving working time. It is mainly used in the filtration of mobile phases and samples in chromatographic analysis, and the filtration of mobile phases and samples in chromatographic analysis. Sample pre-filtration, clarification and particle removal, sterilization and filtration of liquids and gases. The membrane materials of the main syringe filters include water system and organic system. Among them, the water system includes: mixed cellulose (MCE) and polyethersulfone (PES). The organic system includes: nylon (Nylon), polytetrafluoroethylene (PTFE), polyvinylidene fluoride film (PVDF), etc.
Introduction to the use of syringe filter
1. Before inhaling the sample, draw about 1ml of air into the syringe to minimize liquid residue.
2. Aspirate the sample into the syringe, invert the syringe and clear all residues on the top.
3. Connect the syringe filter to the syringe and tighten it lightly to ensure a good seal.
4. Filter the sample in the syringe into the sample bottle, and then follow the steps to maximize the recovery rate.
5. Remove the filter, draw air into the syringe, reconnect the filter head, and push out any residual sample.
Syringe filter precautions
1. Use syringes with a volume of less than 10ml with caution, because the pressure of such syringes is sufficient to burst the syringe filter.
2. Select the filter membrane recommended in the operating procedures.
The selection of syringe filter needs to be determined according to the actual application scenario
Syringe filter is a fast, convenient and reliable filter tool used routinely in the laboratory. It has a beautiful and lightweight appearance and high cleanliness. It is mainly used for sample pre-filtration, clarification and particle removal, liquid and gas sterilization filtration. It is the preferred method for filtering small samples of HPLC and GC. Different types of filters are suitable for samples with different properties. Let us introduce the selection method.
Syringe filter selection method:
1) Hydrophilic sample: use hydrophilic membrane, which has affinity for water and is suitable for filtering water-based solutions. The available membranes are: mixed cellulose ester, polyethersulfone (PES), etc.
2) Strongly corrosive and aggressive organic solvents (Properties: transparent, colorless liquid): generally hydrophobic membranes such as PTFE, Polypropylene (PP) and other material quality filter membranes.
3) Protein solution: Choose a filter with low protein adsorption, such as a PVDF filter. The microporous filter membrane is made by using polymer chemical materials and pore-forming additives after special treatment and smearing on the support layer. It is also used to filter water-based solutions, so it is also called water-based membrane.
4) Ion chromatography: PES membrane is generally considered to be more suitable for the filtration of low inorganic ion solutions.
When selecting a syringe filter, in addition to the above factors, the volume of the sample must also be considered. Usually, when the sample volume is less than 2ml, a 4mm diameter micro filter is selected; when the sample volume is between 2-10ml, a 13mm diameter filter is selected. When the sample volume is greater than 10ml, select a 25mm diameter syringe filter.
The microporous filter membrane of syringe filter is made by using polymer chemical materials and pore-forming additives after special treatment and smearing on the support layer. It is also used to filter water-based solutions, so it is also called water-based membrane. Compared with the solvent filter, the solvent filter is connected by a rubber plug, which is easy to insert and pull. The membrane replacement part above can also be used with the multi-filter bracket, and the combination method is more diverse.